Excitons in a mirror: Formation of “optical bilayers” using MoS{sub 2} monolayers on gold substrates

Journal Article · Mon May 12 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4876475· OSTI ID:22275529

Mertens, Jan; Shi, Yumeng; Molina-Sánchez, Alejandro; Wirtz, Ludger ^[1]

---

1. Physics and Materials Science Research Unit, University of Luxembourg, L-1511 Luxembourg (Luxembourg)

We report coupling of excitons in monolayers of molybdenum disulphide to their mirror image in an underlying gold substrate. Excitons at the direct band gap are little affected by the substrate whereas strongly bound C-excitons associated with a van-Hove singularity change drastically. On quartz substrates only one C-exciton is visible (in the blue) but on gold substrates a strong red-shifted extra resonance in the green is seen. Exciton coupling to its image leads to formation of a “mirror biexciton” with enhanced binding energy. Estimates of this energy shift in an emitter-gold system match experiments well. The absorption spectrum of MoS{sub 2} on gold thus resembles a bilayer of MoS{sub 2} which has been created by optical coupling. Additional top-mirrors produce an “optical bulk.”.

• OSTI ID: 22275529
• Journal Information: Applied Physics Letters, Vol. 104, Issue 19; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTRA
BINDING ENERGY
EXCITONS
GOLD
MIRRORS
MOLYBDENUM
MOLYBDENUM SULFIDES
OPTICAL SYSTEMS
RED SHIFT
SUBSTRATES